Enhanced Stability of Spin-Dependent Chiral 2D Perovskite Embedded PV-Biased Anode via Cross-Linking Strategy

The instability of organic–inorganic halide perovskite (OIHP) absorbers continues to hinder the realization of stable photoelectrochemical water splitting. The bias required for the oxygen evolution reaction triggers the accumulation of dissociated ions from the OIHPs, which induces photocorrosion. To impede this ion migration, we propose a cross-linking strategy that involves using thermal-polymerizated trimethylolpropane triacrylate to reinforce the polymeric network within grain boundaries. Moreover, a photo-cross-linked chiral/achiral mixed 2D perovskite is introduced as a spin polarizer to further enhance the PEC performance. The spin polarizability of the spin polarizer is enhanced by inducing an internal strain. The resulting dual-cross-linked chiral 2D/3D perovskite-based anode exhibited an outstanding stability of 255 h, thereby highlighting the effectiveness of the cross-linking strategy in improving the spin-dependent oxygen production and long-term stability. Furthermore, the perovskite-based cathode and anode, combined as an unassisted coplanar device, exhibit a solar-to-hydrogen efficiency of 11.14% and stable operation for 25 h.